1. Field of the Invention
The present invention relates to a smart key system for an automobile.
2. Description of the Related Art
In a typical smart key system, a driver can unlock his car without inserting the key, and if the smart key is inside the car, the driver can start his car using an ignition switch without inserting the key.
Door antennae mounted on the body of the door handle sense the smart key, thereby unlocking the door. Further, two indoor antennae sense whether the smart key is inside the car and allow ignition.
A body control module (BCM), driver door module (DDM), and an assist door module (ADM) are connected to an immobilizer unit (IMMO unit) and a PIC unit via a controller area network (CAN).
The IMMO unit controls the start-up and is connected to an engine control unit (ECU), and the PIC unit controls the operation of a mechanical steering lock, a door handle, a steering wheel, a door-driving handle, and various antennae.
A diffusion smart key has a knob-type structure in order to start up the car without inserting the key. The car can be started by rotating the knob.
A push-release function is applied when turning the knob from “ACC” to “LOCK” to prevent the knob from being erroneously turned to “LOCK”. The push-release function is an inconvenience to users.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.